Computer hard disc drives (HDD) are subject to environmental stress such as changes in temperature and/or altitude (pressure change) for example. These stresses lead to a change in the air properties between the disc and the read/write head (i.e., slider). This change in air properties can result in a change in the fly height (FH) of the read/write transducer located on the slider. The change in fly height can detrimentally affect recording density by affecting the ability of the read/write transducer to track, resulting in increased bit errors.
The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.